Direct-fired oxidation furnace and waste gas treatment system

Abstract

The utility model relates to a direct combustion oxidation furnace which comprises a shell, a furnace cavity is defined by the shell and provided with a waste gas inlet and a waste gas outlet, the furnace cavity is provided with a first cross section perpendicular to the vertical direction, and the waste gas inlet faces upwards and is communicated with the furnace cavity and the outside. The waste gas inlet is provided with a second cross section perpendicular to the vertical direction, the first cross section is larger than the second cross section, and the waste gas outlet faces the side and is communicated with the furnace cavity and the outside. According to the utility model, most dust cannot be discharged into the heat exchanger from the waste gas outlet along with air, so that the dust is prevented from being deposited on the heat exchanger, and the heat exchange efficiency in the organic waste gas treatment process is ensured.

Description

Technical Field

[0001] This utility model relates to the field of waste gas treatment technology, and in particular to a direct-fired oxidation furnace and a waste gas treatment system. Background Technology

[0002] In the semiconductor organic waste gas treatment process, after the waste gas is desorbed by the zeolite rotor, it is first preheated by the heat exchanger and then enters the TO furnace for combustion. The TO furnace decomposes VOCs into CO2 and H2O at high temperature. The waste gas after combustion recovers heat energy through the heat exchanger and is finally discharged through the chimney.

[0003] Because the exhaust gas contains HMDS (hexamethyldisilazane), it produces dust (SiO2) after combustion. This dust accumulates on the heat exchanger after entering it with the air, leading to reduced heat exchange efficiency, increased fuel consumption, and higher operating costs. Therefore, cleaning and maintenance are required to ensure normal operation. Generally, cleaning is done through the inspection port during annual maintenance. However, cleaning and maintenance are difficult, require a lot of manpower and resources, and cannot completely remove the dust, resulting in low heat exchange efficiency. How to ensure heat exchange efficiency during the treatment of organic waste gas is a technical problem that urgently needs to be solved in this field. Utility Model Content

[0004] Therefore, this utility model provides a direct-fired oxidation furnace and a waste gas treatment system to ensure heat exchange efficiency during the treatment of organic waste gas.

[0005] To solve the above-mentioned technical problems, this utility model provides a direct-fired oxidation furnace, including a shell, which encloses a furnace cavity and is provided with an exhaust gas inlet and an exhaust gas outlet. The furnace cavity has a first cross-section perpendicular to the vertical direction. The exhaust gas inlet faces upward and connects the furnace cavity with the outside. The exhaust gas inlet has a second cross-section perpendicular to the vertical direction. The first cross-section is larger than the second cross-section. The exhaust gas outlet faces sideways and connects the furnace cavity with the outside.

[0006] Furthermore, the top of the shell is a hemispherical head, and the exhaust gas inlet is located at the top of the hemispherical head.

[0007] Furthermore, the hemispherical head is also provided with an installation port for installing a burner.

[0008] Furthermore, the middle part of the shell is a cylinder, and the exhaust gas outlet is located on the cylinder.

[0009] Furthermore, the cylinder is also provided with a side-facing inspection port, which is connected to an inspection door.

[0010] Furthermore, the bottom of the shell is a cone, with the small end of the cone facing downwards. The small port of the cone is a dust removal port, and the dust removal port is connected to a dust removal device.

[0011] Furthermore, the dust removal device is a drawer-type dust removal box or an electric leakage device.

[0012] Furthermore, a ceramic insulation layer is detachably connected to the inner wall of the shell.

[0013] This utility model also provides a waste gas treatment system, including:

[0014] A heat exchanger having a first heat exchange channel and a second heat exchange channel for heat exchange;

[0015] A desorption device, wherein the exhaust gas outlet of the desorption device is connected to the inlet of the first heat exchange channel;

[0016] The direct-fired oxidizer has its exhaust gas inlet connected to the outlet of the first heat exchange channel, and its exhaust gas outlet connected to the inlet of the second heat exchange channel.

[0017] Furthermore, the heat exchanger is a plate heat exchanger.

[0018] Compared with the prior art, the above-mentioned technical solution of this utility model has the following advantages: In the direct-fired oxidation furnace of this utility model, after the organic waste gas enters the furnace cavity from the waste gas inlet, since the cross-section of the waste gas inlet is smaller than the cross-section of the furnace cavity, it is a variable diameter form. The air suddenly enters from the small opening to the large opening. The flow rate remains unchanged and the wind speed will decrease sharply. The air in the waste gas is discharged from the waste gas outlet. The particulate dust in the waste gas will maintain inertia and impact the bottom of the furnace cavity at high speed. The dust will not be discharged from the waste gas outlet with the air and enter the heat exchanger, thereby preventing dust from depositing on the heat exchanger and ensuring the heat exchange efficiency in the organic waste gas treatment process. Attached Figure Description

[0019] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0020] Figure 1 This is a top view of the direct-fired oxidation furnace in this utility model;

[0021] Figure 2 for Figure 1 Schematic diagram of section AA;

[0022] Figure 3 for Figure 1 Schematic diagram of the BB section;

[0023] Figure 4 This is an axial view of the direct-fired oxidation furnace in this utility model.

[0024] Explanation of reference numerals in the accompanying drawings: 1. Shell; 11. Hemispherical head; 12. Cylinder; 13. Conical cylinder; 21. Furnace cavity; 22. Exhaust gas inlet; 23. Exhaust gas outlet; 24. Installation port; 25. Inspection port; 26. Ash removal port; 3. Inspection door; 4. Ash removal device. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0026] Example 1: See Figures 1 to 4 As shown, this utility model provides an embodiment of a direct-fired oxidation furnace.

[0027] The direct-fired oxidizer includes a shell 1, which encloses a furnace cavity 21 and is provided with an exhaust gas inlet 22 and an exhaust gas outlet 23. The furnace cavity 21 has a first cross-section perpendicular to the vertical direction. The exhaust gas inlet 22 faces upward and connects the furnace cavity 21 with the outside. The exhaust gas inlet 22 has a second cross-section perpendicular to the vertical direction. The first cross-section is larger than the second cross-section. The exhaust gas outlet 23 faces to the side and connects the furnace cavity 21 with the outside.

[0028] The aforementioned direct-fired oxidizer is a vertical TO furnace. The sizes of the first and second cross-sections should be sufficient to separate air and dust in the exhaust gas. Generally, the first cross-section should be twice the size of the second cross-section. After the organic waste gas enters the furnace chamber 21 through the waste gas inlet 22, since the cross-section of the waste gas inlet 22 is smaller than that of the furnace chamber 21 (it is a variable diameter type), the air suddenly enters from the small opening to the large opening. The flow rate remains constant, but the wind speed decreases sharply. The air in the waste gas is discharged from the waste gas outlet. The particulate dust in the waste gas will maintain inertia and impact the bottom of the furnace chamber 21 at high speed. The dust will not be discharged from the waste gas outlet 23 with the air and enter the heat exchanger, thereby preventing dust from depositing on the heat exchanger and ensuring the heat exchange efficiency in the organic waste gas treatment process.

[0029] In this embodiment, the top of the housing 1 is a hemispherical end cap 11, and the exhaust gas inlet 22 is located at the top of the hemispherical end cap 11.

[0030] A hemispherical head (11) refers to a head consisting of a half-spherical shell and a straight edge (a short cylindrical section). The hemispherical head ensures that the radius of curvature of the shell is uniform throughout, resulting in uniform stress distribution. Compared to other heads, the hemispherical head requires the least wall thickness to withstand the same internal pressure. At the junction of the spherical shell and a cylinder of the same thickness, the edge stress caused by the change in radius of curvature is only 3.1% of the overall membrane stress of the cylinder, which is negligible. Therefore, the hemispherical head exhibits the best mechanical properties and uses the least amount of material.

[0031] In this embodiment, the hemispherical head 11 is further provided with an installation port 24, which is used to install a burner.

[0032] After the exhaust gas enters the furnace chamber through the exhaust gas inlet 22, it needs to be burned. A burner can be installed through the installation port 24. The combustion end of the burner is located in the first inner cavity and can burn the exhaust gas passing through the first inner cavity.

[0033] In this embodiment, the middle part of the housing 1 is a cylinder 12, and the exhaust gas outlet 23 is located on the side wall of the cylinder 12.

[0034] The cylinder 12 has a cross-section perpendicular to the vertical direction, and the cross-section of the cylinder 12 is the same from top to bottom.

[0035] In this embodiment, the cylinder 12 is also provided with a side-facing inspection port 25, and the inspection port 25 is connected to an inspection door 3.

[0036] Direct-fired oxidizers require regular maintenance. Inspection port 25 allows for internal inspection. Inspection port 25 is typically large, facilitating easy access and repair of the furnace cavity. When the direct-fired oxidizer is operating, the inspection door 3 is closed; when not operating, the inspection door 3 is open, allowing personnel to inspect the interior of the furnace cavity 21 through inspection port 25.

[0037] In this embodiment, the bottom of the housing 1 is a cone 13, the small end of the cone 13 faces downward, the small end of the cone is a dust removal port 26, and the dust removal port 26 is connected to a dust removal device 4.

[0038] After the direct-fired oxidizer has been working for a period of time, a lot of dust will accumulate in the furnace chamber 21, requiring cleaning. This is achieved by setting up a dust removal port 26. When the direct-fired oxidizer is working, the dust removal device 4 is located at the dust removal port 26; when the direct-fired oxidizer is not working, the dust removal device 4 is used for cleaning. The aforementioned cone 13 allows dust and powder to fall and accumulate in one place.

[0039] In this embodiment, the above-mentioned dust removal device 4 is a drawer-type dust removal box.

[0040] The drawer-type dust removal box is drawer-shaped and connected to the dust removal port 26. When the direct-fired oxidizer is working, the dust entering the cone 13 falls into the drawer-type dust removal box. When the direct-fired oxidizer is not working, the dust in the drawer-type dust removal box can be cleaned periodically.

[0041] In this embodiment, a ceramic insulation cotton layer (not shown in the figure) is detachably connected to the inner wall of the shell 1.

[0042] Ceramic insulation cotton, also known as ceramic fiber cotton, is a high-performance ceramic fiber cotton made from raw materials such as aluminum silicate, silicon dioxide, and silicon nitride. Due to its excellent heat resistance and insulation properties, it is widely used in high-temperature insulation applications to prevent heat loss from furnaces.

[0043] This utility model also provides a waste gas treatment system, including:

[0044] The heat exchanger has a first heat exchange channel and a second heat exchange channel for heat exchange.

[0045] The desorption device has its exhaust gas outlet connected to the inlet of the first heat exchange channel.

[0046] The aforementioned direct-fired oxidizer has its exhaust gas inlet connected to the outlet of the first heat exchange channel, and its exhaust gas outlet connected to the inlet of the second heat exchange channel.

[0047] A heat exchanger is a device that transfers part of the heat from a hot fluid to a cold fluid; it is also called a heat exchanger. The desorption device described above is a zeolite rotor desorption device. The exhaust gas discharged from the zeolite rotor desorption device is approximately 100 degrees Celsius. After passing through the heat exchanger, it exchanges heat with the exhaust gas discharged from the direct-fired oxidizer, and is heated to approximately 400 degrees Celsius. Finally, it is burned in the direct-fired oxidizer to a temperature of over 760 degrees Celsius, completing the exhaust gas combustion treatment.

[0048] In this embodiment, the heat exchanger is a plate heat exchanger.

[0049] Commonly used heat exchanger types are tubular heat exchangers and plate heat exchangers. Compared to plate heat exchangers, tubular heat exchangers are relatively easier to clean, while plate heat exchangers have higher heat exchange efficiency. In this invention, because the amount of dust entering the heat exchanger is greatly reduced, a plate heat exchanger with higher heat exchange efficiency can be used, further improving the heat exchange efficiency in the organic waste gas treatment process.

[0050] Example 2: The rest is the same as in Example 1, except that the above-mentioned dust removal device is an electric leakage device.

[0051] The electric leakage device is an electric sealing cover. During the operation of the direct-fired oxidizer, the electric sealing cover closes the ash removal port. When the direct-fired oxidizer is not working, the sealing cover can be opened electrically to allow the dust and powder in the cone to be discharged from the ash removal port into the furnace chamber.

[0052] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A direct-fired oxidation furnace, characterized in that, The device includes a shell that encloses a furnace cavity and has an exhaust gas inlet and an exhaust gas outlet. The furnace cavity has a first cross-section perpendicular to the vertical direction. The exhaust gas inlet faces upward and connects the furnace cavity to the outside. The exhaust gas inlet has a second cross-section perpendicular to the vertical direction. The first cross-section is larger than the second cross-section. The exhaust gas outlet faces sideways and connects the furnace cavity to the outside.

2. The direct-fired oxidation furnace according to claim 1, characterized in that, The top of the shell is a hemispherical head, and the exhaust gas inlet is located at the top of the hemispherical head.

3. The direct-fired oxidation furnace according to claim 2, characterized in that, The hemispherical head is also provided with an installation port for installing a burner.

4. The direct-fired oxidation furnace according to claim 1, characterized in that, The middle part of the shell is a cylinder, and the exhaust gas outlet is located on the cylinder.

5. The direct-fired oxidation furnace according to claim 4, characterized in that, The cylinder is also provided with a side-facing inspection port, which is connected to an inspection door.

6. The direct-fired oxidation furnace according to claim 1, characterized in that, The bottom of the housing is a cone, with the small end of the cone facing downwards. The small port of the cone is a dust removal port, and a dust removal device is connected to the dust removal port.

7. The direct-fired oxidation furnace according to claim 6, characterized in that, The dust removal device is a drawer-type dust removal box or an electric leakage device.

8. The direct-fired oxidation furnace according to claim 1, characterized in that, A ceramic insulation layer is detachably connected to the inner wall of the shell.

9. A waste gas treatment system, characterized in that, include: A heat exchanger having a first heat exchange channel and a second heat exchange channel for heat exchange; A desorption device, wherein the exhaust gas outlet of the desorption device is connected to the inlet of the first heat exchange channel; The direct-fired oxidizer according to any one of claims 1 to 8, wherein the exhaust gas inlet of the direct-fired oxidizer is connected to the outlet of the first heat exchange channel, and the exhaust gas outlet of the direct-fired oxidizer is connected to the inlet of the second heat exchange channel.

10. The waste gas treatment system according to claim 9, characterized in that, The heat exchanger is a plate heat exchanger.

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